The present invention relates to semiconductor packaging in general and more specifically to a brace for a long bond wire to prevent the bond wire from short circuiting.
Wire bonding typically involves connecting a bond pad on an integrated circuit (IC) die to a lead finger of a lead frame with a bond wire. Referring to FIG. 1, a conventional wire bond connection 10 is shown in which a bond wire 12 has one end attached to a bond pad of an integrated circuit die 14 with a ball bond 16 and a second end attached to a lead finger 18 of a lead frame (or to a connection pad of a substrate) with a stitch bond 20.
As die sizes have been shrinking, bond pads on the die, which were traditionally located only along a perimeter of the top surface of the die, now are located both near and far from the die edges, oftentimes in an array format on the top surface of the die. Thus, some of the bond wires, like the wire 12 shown in FIG. 1, are relatively long, extending from a middle or central area of the die 14 to the lead finger 18.
When the bond pad on the die is near to the edge of the die, the loop height of the wire prevents the wire from touching the edge of the die, which would cause a short circuit. However, the long bond wires connecting these further from the edge die pads to the lead frame are susceptible to sagging or drooping, as shown in FIG. 1, in which case they may inadvertently contact the edge of the die 14.
Further, during an encapsulation process, when the die and bond wires are being covered with a mould compound, when the mould compound flows over the surface of the die, such long wires are susceptible to moving laterally, known as wire sweep, causing them to contact other wires. These problems have become more acute as the diameter of the bond wires have decreased.
Thus, it would be advantageous to have bond wires that will not touch the edge of the die or contact other bond wires.